I use a 3.9 Supra diff in my focus witch was running around 400bhp 4x4 . and my mate is 2wd with just under 500bhp we both run 18 inch wheels and in the courner and as we get up to about 120 he can not live we my focus running the 3.9 diff . I will try and link the video up.

If you copy and past this into gooGoo the video will play . My mate comes up behind me at a bout 2.30 min in

https://youtu.be/ER7rIFSXxgY